How do you refactor?

Question

I was wondering how other developers begin refactoring. What is your first step? How this process (refactoring) differ if you refactor code which is not yours? Do you write

Answer 1

I take crap and make it less crappy. :-)

Seriously. I don't refactor to create new functionality. Refactoring occurs before new stuff. If there are no tests I write tests to make sure that I'm not breaking anything with my refactoring. If there are tests, I use those. If the tests are insufficient, I might write more tests but I would consider this separate from the refactoring and do it first.

The first step for me is to notice that I can abstract something and make it more general (and useful in other places that need the functionality now), or I notice that something is bad and could be better (subjective). I don't refactor to generality without a reason. YAGNI principle applies.

We have the concept of shared ownership so the code is always mine -- I may not have written it, but I don't consider that when refactoring. I may seek to understand things before I decide it needs refactoring if the purpose isn't clear -- although that's almost always a reason to refactor in and of itself.

Answer 2

I'm a lot more reluctant to refactor code written by others than to refactor my own.

If it's been written by one of my predecessors, I generally refactor only within a function. E.g. I might replace an if statement with a switch. Anything much bigger than that is usually out of scope and not within budget.

For my own code, I usually refactor as I'm writing, whenever something looks ugly or starts to smell. It's a lot easier to fix it now instead of waiting for it to cause problems down the road.